Commutator-bar for dynamo-electric machines



(No Model.)

0. E. BILL'I'NGS.

GOMMUTATOR BAR FUR DYNAMO ELEGTRIG MACHINES.

No. 392,490. Patented Nov. 6, 1888.

UNITED STATES Farmer CHARLES E. BILLINGS, OF HARTFORD, CONNECTICUT.

CCMMUTATOR-BAR FCR DYNAMG=ELECTRZC MACHINES.

SPECIFICATION forming part of Letters Patent No.392,490, dated November 6, 1888.

Application filed December 4, 1866. Serial No. 220,076. (No model.)

To aZZ whom, it may concern: nect arm 2 with the appropriate coils, bars,

Be it known that I, CHARLES E. BILLINGS, or segments of the rotary armature of the maof Hartford, Connecticut, haveinventedancw chine to which the commutator is applied. and useful Commutator-Bar for DynamoElec- This bar is usually wedge-shaped in cross-sec- 5 5 5 trio Machines, which is described in the foltion and provided with terminal projections 4 lowing specification and is illustrated by the anl 5, by means of which it may be clamped accompanying drawings. in its appropriate position about the armature- This invention relates to commutators of shaft, as seen in Fig. 2. dynamo-electric machines, whether motors or The method or process which I adopt for 60 1O generators; and it consists of a commutatorthe manufacture of myimproved commutatorbar, a commutator-strip, or a segment of bar above described is the ordinary process of the commutator, variously so called, which is drop-forging, and proceeds in the following formed of a single piece of pure copper and manner: A cylindrical rod of copper, being has two arms whose longitudinal axes form an out to the requisite length, is heated to a mal- 65 angle with each other. leable state, and while in that condition is sub- Commutator-barshaveheretofore been made jected to the action of successive pairs of dies of a single piece of brass, bronze, or other elecin a drop-press. By the first pair of dies the trically-conductive alloy cast in the described so-called operation of breaking down and form, but on account of the difficulty of cast drawing the rod is completed. In asecond 0 ing pure copper have not been made of a sinpair of dies the rodis bent and the arms 2 and gle piece of that metal in the specified form. 3 receive their relative direction. In a third Com mutator-bars have also been made in two pair of dies the bent copper strip while still arms separately constructed, and soldered, hot is subjected to the so-called operation of screwed, or otherwise joined together. Acstriking up, which producesin arough and 75 cording to this method the main arm of the ragged state the designed or specified form. commutator-bar has sometimes been formed The bar is then treated with acid for the purof pure copper rolled or drawn, and the repose of removing oxide. .Vhen cold, the pro inaining arm, on account of the ditliculty alduct is trimmed in the usual manner. By this luded to, has been formed of brass or other means I supply a commutator of pure copper SC,

material cast in the desired form. in the typical form above described, or in any The object of the present invention is to desired modification of that form, and at the supply a commutatonbar of pure copper in same time avoid the disadvantages, both me the described typical form, and by so doing to chanical and electrical, which are involved in avoid the disadvantages, both mechanical and using two pieces of metal or any other metal, 8

electrical, which are involved in unitin two than unalloyed copper in a commutatonbar. pieces of metal or in using other substances Still another advantage possessed by this than unalloyed copper for the purpose of formcommutator-bar lies in this, that, being formed ing a commutator-bar. from asingle copper rod by the process of In the accompanying drawings, illustrative drop-forging, it has the grain or fiber of the 0 of my invention, Figure 1 is a perspective material always parallel to the axis of the view of my improved commutator-bar. Fig. commutatonbar, no matter in what shape the 2 is a side view of the same induplicate, showsame may be bent. This also is an important ing the position of the same in a commutator. point, as heightening the conductivity and Fig. 3 is an end view of three such bars in podurability of the article. 5

+ sition in a commutator. In the preferred form of my commutator- In the views the numeral 1 denotes the combar the outstanding arm has a projection or mutator-bar. The form of this bar admits of lug, 6, by which it may be connected convenconsiderable variation. It is essential, howiently to the coils of the armature. ever, that the bar should have a main arm, 2, Itis one of the great advantages of this com- 100 which is rubbed by the brushes of the dynamo, mutator-bar as made by my process of dropand a secondary arm, 3, which serves to conforging that it maybe made of any desired and convenient shape, however complex, and still be of but one piece of metal, homogeneous in molecular structure throughout, and of that great density which is produced by the process of drop-forging, and which is such a desirable quality in a commutator-bar, as affording a high degree of conductivity.

I claim 1. As an article of manufacture, a full-sized commutator-bar for dynamo-electric machines which has two arms whose longitudinal axes form an angle one with the other, and which is composed throughout of one single piece of unalloyed copper of an almost perfectly homogeneous molecular structure, the fiber 0r grain of the copper-being so arranged as to be everywhere parallel With the axis of the arm and of the greatest possible density, substantially as and for the purpose described.

2. As an article of manufacture, afull-sized comm utator-bar for dynamo-electric machines,

which bar as to its shape has two arms whose axes make an angle one with the other, one of which arms has suitable projections at its ex tremities, by which it may be clamped to the armature-shaft, While the other arm has at its outer extremity asuitable lug or projection, by which it may be connected to the armaturecoils, and which bar as to its structure consists of one single piece of unalloyed copper almost perfectly homogeneous throughout, the fiber or grain of the copper being so arrangedas to be everywhere parallel With the axis of the arm and of the greatest possible density, substantially as and for the purpose described.

In testimony whereof I have hereunto set my name in the presence of two witnesses.

CHARLES E. BILLINGS.

Witnesses:

FRED. O. BILLINGS, WILLARD EDDY. 

